


Tease

by 0neType



Category: Undertale (Video Game)
Genre: Begging, Bondage, Crying, Cunnilingus, Dirty Talk, Edging, Established Relationship, Foursome - M/M/M/M, Kissing, Large Breasts, M/M, Making Out, Multi, Nipple Play, Orgasm Delay, PWP, Praise Kink, Romance, Sibling Incest, Smut, Teasing, Tit Play, Undertale Multiverse
Language: English
Status: Completed
Published: 2020-10-25
Updated: 2020-10-25
Packaged: 2021-03-09 07:07:49
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,564
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27199612
Author URL: https://archiveofourown.org/users/0neType/pseuds/0neType
Summary: Nightmare is a King.It's only right that his most loyal subjects serve him.(Even if they insist on dragging it out until he's begging.)
Relationships: CrossMare - Relationship, DreamMare - Relationship, Kight - Relationship, Killer/Nightmare/Dream/Cross, KillerCreamMare, NightKiller - Relationship, Nightmare/Cross, Nightmare/Dream, Nightmare/Killer
Comments: 24
Kudos: 279





	Tease

**Author's Note:**

> Taking a break from longfics to post some unrelated KCRM smut!! >:D
> 
> The premise is based on **[a tweet made by Neah](https://twitter.com/NeahChanArt/status/1319883978871050241)** which had us all thirsting. 💦 Wrote this all real quick so please don't be surprised if you come back a day or two from now and there's been a couple (or a dozen) edits made AHAHAHA 😂
> 
> In any case, please enjoy!!

Without a doubt, this is simultaneously the best and the worst thing that Nightmare has ever agreed to.

He’s restrained, arms bound to his headboard, and feet tied to either post at the foot of the bed. It’s the sort of thing he absolutely would not have allowed just a few months ago. His pride and inherent distrust of others kept him from it, an ugly, black revulsion to the mere idea of being so vulnerable.

And yet, after some gentle coaxing from his partners, the idea has become an appealing one. The thought of having all three of them pleasuring him, their attention focused solely on his satisfaction—that sounded more than excellent. So what if he were bound during it? He was a King, and they would serve him as such.

Or so he’d thought at the time.

Now, Nightmare struggles against his bonds, gasping as Dream smoothes a careful, gloved hand over the side of his face. His wet pants are swallowed down as his brother closes his mouth over Nightmare’s, tongue skillfully licking into him and rendering him further breathless. Nightmare is almost grateful for the way Dream muffles the noises that break out of him, humiliating as they are. He whimpers and keens into Dream’s mouth, body tensing and untensing as Killer and Cross continue their work uninterrupted.

Killer sits across his middle, legs spread on either side of him. He’d used his knife earlier to cut straight up the middle of Nightmare’s turtleneck, exposing his ribs. Then, he’d worked his hands over Nightmare’s chest, rubbing and stroking and finally bending down to lick and suck at the bone until Nightmare’s magic had no choice but to form. His chest had swollen with warm, soft breasts that Killer had immediately leered at with a wicked-satisfied grin.

As for Cross, he’s taken his place in between Nightmare’s legs, bending them up and spreading them wide. They’re still secured to the bedpost, but there’s enough give that Cross can easily position himself where he needs to be. And where he needs to be is apparently right at his pubis, breathing hot, tantalizing breaths over his symphysis before running his tongue over the area slowly. It’s a tease, right from the start, and it doesn’t take long before the combined sensations from Dream, Killer and Cross, has Nightmare’s pussy dropping into place, already dripping with arousal.

Which brings him right back to gasping into Dream’s mouth, face scalding with teal blush.

His brother pulls away with a smile. “You doing okay, Night?”

“Dream…” He manages to breathe out, a strained tension to his voice as the stimulation continues all over his body. It’s too much to focus on at once, but not enough to do more than wind him up. The touches are light, teasing—a frustrating combination that’s had him on the cusp of coming for ages now.

“Shh.” Dream strokes the side of his face again, dipping down to press another short kiss to his teeth. “Just let us take care of you, brother.”

He wants to bite out something sarcastic, regain a little control of the situation, but when he opens his mouth, all that escapes is a desperate moan. It’s born out of the sensation Cross evokes in him, his femurs trembling as Cross rubs two fingers up and down the slit of Nightmare’s cunt, getting them wet with slick before gently smearing it over his outer folds and glancing over the hood of his clit. Nightmare pushes his hips down, eager for more, but Cross holds a hand steady at his hip, keeping him in place.

“Easy, boss,” Cross murmurs, voice low. He rubs a thumb in circles at the jut of Nightmare’s pelvis. It’s probably meant to be soothing, but it only drives Nightmare that much wilder, a frenzied urge to be brought to release.

“ _Hurry up_ ,” he manages to bite before Dream silences him with another kiss.

“Someone’s being a little impatient, huh?” Killer chuckles, cupping Nightmare’s tits in his hands. “ _‘Good things come to those who wait’_ , Nightlight.”

He wants to glower at Killer for the blatant badgering and the stupid nickname—shut him up with a well placed verbal jab—but Cross takes that exact moment to lower his head down. He drags the rough, flat of his tongue over Nightmare’s cunt from his dripping hole to his already sensitive clit. It has him choking back a moan, the tension only amplified by the way Dream kisses along his jaw and then makes his way down Nightmare’s neck, nipping and sucking as he goes.

“Yeah, you like that, Night?” Killer purrs, squeezing his tits in each palm and then pressing them up together. The look in his eye is downright filthy, and even if Nightmare couldn’t read his emotions, it’s easy enough to see the lecherous intent flaring hot in Killer’s singular eyelight.

“Fuck boss, every part of you is so damn soft,” Killer whispers, running his thumbs over Nightmare’s nipples. They’re still sunken in, not yet aroused enough to become erect, but Killer doesn’t seem to mind in the slightest, continuing to rub circles over the sensitive nubs. “Wanna take my time touching you all over.”

Nightmare’s face glows bright with his magic, a sudden embarrassment overwhelming him at how he must look right now. He’s supposed to be King. He’s supposed to be all powerful. And yet, here he lies, rendered a mess with a few touches.

His legs are spread, his cunt wet and messy, as Cross continues to work him over with gentle, barely there, kitten licks that amp up the pressure mounting inside of him even further. Killer bounces his tits, the magic so large and full that it peeks over obscenely out of his cupped hands. And, of course, Dream resumes kissing him all over—soft, breathy things that radiate a shock of genuine love and affection.

It’s a lot.

It’s _so much_.

He takes a shaky breath in, trying to ground himself even as Cross’ tongue delves inside of him, curling. His legs shake and he desperately tries to close them, but the restraints keep him held bare, exposed to Cross as he drinks down Nightmare’s wetness, tongue tasting him deep. He feels edged right over the precipice of relief, his clit throbbing with a phantom release that Nightmare wishes he could experience. He clenches around Cross’ tongue, moaning aloud, voice breaking in forlorn desire. Cross hums in pleasure.

His vocal submission is rewarded—Cross inserts two fingers in alongside his tongue, working them quickly in and out as he goes from licking to sucking.

“You’re doing amazing, Night,” Dream praises him, and Nightmare makes another humiliating noise, torn apart by the sweetness. Dream knows how to break him down with words alone, careful adoration and honest affection rendering Nightmare meek and subservient. He’s pliant as Dream tilts his head up for another kiss, tongue slipping into his mouth once more. Dream sighs, blissed out and approving, “You’re beautiful.”

“Damn right, he is,” Killer interjects, and Nightmare’s attention is immediately taken in by the glint in his eyelight and the sharp point to his grin. That’s the look Killer gets when he has a plan. Nightmare’s soul kicks up into a frantic pace, body tensing at the thought of what it could possibly be.

“Tastes good too,” Cross says, pulling back and wiping his mouth on the edge of his palm.

The visual, combined with the sudden press of Cross’ magic beneath him, hot and firm, has Nightmare’s false throat going dry. As if noticing exactly that, Cross rocks his hips forward, letting Nightmare fully feel the size of him, pressed right in between his folds. It’s all he can do to keep from grinding down on Cross’ clothed cock with a wanton moan, still clinging to the shreds of his pride and refusing to debase himself like that.

Even if all he can imagine is being speared open on Cross’ thick length, every inch of him filled and used to completion.

“I think he’s ready for more,” Dream laughs, and too late Nightmare remembers that Dream can sense his emotions with ease. He glares at his brother, blush brightening, but Dream only presses another kiss to his face. “Don’t be mad, Night. We’re going to make you feel amazing.”

“Yeah, boss,” Killer says, and Nightmare is reminded again of the intensity of his gaze when Killer gives him a crooked little grin. “Let us show you a real good time.”

And then, Killer ducks his head and seals his mouth around a nipple.

In an instant, Nightmare’s back is arching, his restraints going tight. He gasps aloud, twisting in place as Killer teases his in-turned nub with his tongue, flicking along it back and forth. When he pulls away, he only does so long enough to breathe a cool, wet breath along the slickened magic before taking the other nipple into his mouth and repeating his earlier motion.

“Killer—” Nightmare starts, but can’t finish the words when said monster takes a nipple gently between his teeth and tugs.

It has Nightmare clenching his sockets shut, arms jolting forward with the urge to free himself, to put his hands at Killer’s skull; to push him away and pull him close at the same time. All the while, Killer continues to flick over his nipples with his tongue, licking and pulling at them in turns, back and forth. It has Nightmare zeroed in on that and nothing else, mouth opening and closing as he tries and fails to say something.

As Killer finally manages to coax his nipples to hardness, he pulls back with a grin, looking absolutely shameless. “How you feeling, boss?”

“Annoyed,” Nightmare pants, trying to frown but too caught up in calming his racing soul.

“He’s lying,” Dream sighs, shaking his head in mock admonishment. “Honestly, brother, is it so hard to admit that you feel excited?”

Nightmare flushes harder, turning his face to the side in an attempt to hide his faltering expression.

“I think we can tell pretty easily how excited he is,” Cross muses. When Dream looks at him, questioning, Cross points at the very obvious teal slick trailing down his chin. “He gets wetter and wetter with every touch. Forget tongues and fingers—he could probably take all three of us inside him at once with how eager he is.”

The image Cross’ words create set his soul alight. His body feels hot all over, his cunt clenching around emptiness and a deep-seated need overtaking him. He can just about feel how full they’d get him. How they’d stretch him out. How they’d use him over and over until he was dripping cum, thoroughly claimed.

He grits his teeth to keep from saying anything he’d regret.

Not that it helps when Dream immediately catches onto his interest and reveals it to the rest.

“He likes that,” Dream breathes, sounding more than a little wrecked himself. Like maybe the idea appeals to him just as much. “Oh, Night… we’re going to ruin you.”

Nightmare’s pussy throbs, aching with that promise. And because it’s Dream, and because it’s easier to let go when it’s his brother, Nightmare turns his head back to look at him, voice low and whispering, “Please.”

“Fuck.” He hears Killer say, but his gaze stays affixed on his brother and the way Dream’s eyelights soften with a heartfelt love that has Nightmare laid bare.

Dream presses a kiss to the top of his skull. “Of course, brother.”

Immediately after, Dream nods in Killer and Cross’ direction, wordlessly conveying instructions they must have discussed long before they began. And then, Nightmare loses thread of anything past what he can feel—all three of them quickly retaking their earlier tasks and overwhelming him once more.

This time, when Dream kisses him, it’s nothing short of claiming. He runs his hands over the back of Nightmare’s skull, pulling him in and kissing him deep. Nightmare can’t help the way he whimpers, Dream sucking and nipping at his tongue before breaking free. He keens as Dream sucks a mark onto his jaw, teasing the newly formed bruise with his tongue and whispering praises as he goes.

Killer returns to playing with his tits, squeezing them and tugging gently at the nipples between his fingers. It makes Nightmare squirm and stutter through bitten off noises that he can’t restrain. Killer chuckles at it, pleased as he takes a breast into his mouth and suckles on it, making Nightmare cry out in pleasure. His chest is sensitive, so rarely formed and used that each touch and lick and bite from Killer feels amplified a dozen times over. Nightmare cries out again when Killer teases a nipple in between his teeth, pulling at them, and tears spring to his sockets from overstimulation.

He feels like he should be able to come, just from this, but although his whole body feels wound up, electric sparks all over—he remains hanging just over the edge, completion just beyond his reach.

“Please,” he says again, _begs_ , out loud, before he can even hold himself back. “Please, _please_ , fuck—”

“You got it boss,” Killer whispers, and his voice is so soft that Nightmare knows without looking that his soul must be heart-shaped. It makes him want to shy away, blush blooming on his cheekbones, even as Cross’s grip slackens on his femurs.

The move confuses Nightmare, and he makes a questioning noise before he feels the tethers at his ankles fall open, the bonds anchoring him to the bed posts released. He shifts in place a little, peering at Cross as best he can.

Looking at Cross directly is a mistake.

There’s a fierceness in Cross’ sockets, determined in a way that makes Nightmare’s soul pound hard against the underside of his ribcage. He feels it all the way up in his throat, gazes locked as Cross reaches out and places Nightmare’s legs over his shoulders. He knows what’s coming, even before Cross drops his head down, but he’s too far gone to stop his stuttered gasp as Cross plunges his tongue into him, deep and curling. He follows it with two fingers, then three, wasting no time in curving them upwards towards the sensitive spot inside of him.

As Cross tongue-fucks him, Killer resumes kneading his breasts, sucking on one while keeping the other busy with his hands. Meanwhile, Dream leans down and hooks a thumb into Nightmare’s mouth, leaving him unable to bite back any noises he makes, tears spilling over his socket at last.

“So pretty,” Dream praises, and at the angle they’re sitting at, Nightmare can easily see the bright golden glow centered in Dream’s pelvis. It both embarrasses and pleases Nightmare to know that he could arouse Dream just like this, just while watching him be taken apart.

“After you come,” Dream says, whispering into the side of skull, words interspersed with gentle kisses. “We’re all going to fuck you. Over and over again until we’re satisfied. Would you like that?”

He’s beyond words, Dream’s promise sending a renewed bolt of desire pulsing through him, his cunt slickening further, clenching tight in a way that makes Cross groan. The vibrations go all the way up to his clit and Nightmare whimpers desperately, arms twisting where they’re still held taut to the headboard.

“I bet he would,” Killer adds, and this time when he pulls away from Nightmare’s chest, a string of saliva trails down his chin. “I bet he’d love it if we tied him up and kept him in here for days, naked and held completely exposed. We’d check in from time to time, of course. Keep him company. Fill him up with cum. Ain’t that sound nice, sweetheart?”

“He’s our King,” Cross murmurs, pulling out of him with a wet _shlick_. “We’ll serve him in any way he needs. Even if he’s too proud to ask for it.”

It’s a direct hit, Nightmare’s face burning.

If his partners discuss things further, he’s unaware of it, lost in the way emotions swell up in his chest. For all that he's the guardian of negativity, he's always been subject to both sides of the spectrum. There's a flood of sweet feeling that he often pretends not to have, soft and warm and unfamiliar. It has a hold on him, this devotion from monsters he calls his own. Their love and loyalty and stalwart adoration. It’s overwhelming in its own right to know he feels the same in return.

But he can’t think on it for too long, the tension coiled tight inside him fit to burst. There’s an added pressure where Killer is straddling him, the weight of his cock pressing into Nightmare’s false flesh. Killer’s rocks back and forth against him, blessedly quiet as he tongues at Nightmare’s chest. His sockets are shut in concentration, browbones furrowed as he suckles, the sensation tingling through Nightmare and making his pussy throb.

Cross has long since started teasing around his clit, running his tongue in circles just outside it, stopping short of touching it directly. Nightmare groans, femurs shaking, and Cross soothes a hand down one of them, reassuring. He follows it with a flick of his tongue, just beneath the hood of his clit, and Nightmare yelps.

“Are you close, Night?” Dream asks, soft, adoring, and every bit as warm as the sun in the summertime.

“Yes,” Nightmare croaks, and then Cross draws his slickened fingers out of his cunt, rubs them firm against the swollen nub of his clit, and Nightmare tips over from close to coming in an instant.

He can't verbalise his relief, can’t say anything coherent at all—it’s all one drawn out sound, his head thrown back as Cross continues to rub quick over him, tonguing at him at the same time. His pussy throbs, clenching over and over, the tension unspooling from every limb with each heavy pulse. Killer doesn’t let up either, grinding down in earnest now as he sucks and nips and tugs at his tits, working him over. Dream holds him steady through it all, whispering praise and endearments and stroking the side of Nightmare’s face, wiping away the tears that stream down it.

When the last of the aftershocks subside, Nightmare feels boneless and floaty. He barely notices it when Dream kisses him and undoes the restraints keeping his arms up. He tries to nuzzle into him afterwards, belated, and Dream laughs a little before giving him another peck.

“Do you want to rest before we continue?” he asks, and it takes a minute for Nightmare to remember what he’s talking about.

He makes a noise of confusion, puzzled, before Killer moves off of him and shifts up to Dream’s position. Cross also moves, pressing a kiss to the inside of Nightmare’s slick-covered femur and then lowering Nightmare’s legs down as he reorients himself by Nightmare’s chest, where Killer was only moments ago. He stares down at his tits with obvious desire, a blush deepening on his cheekbones. It’s only when Killer pulls down his shorts, revealing the leaking length of his neglected cock that Nightmare startles with memory of what's to come.

“We could stop,” Dream offers.

“Yeah,” Killer says, giving himself a languid stroke in a way that has Nightmare swallowing tight. “You could even watch us instead while you rest up.”

The sound of fabric shifting has Nightmare looking back at Cross who’s also drawn his shorts down, his dick just as hard and at attention as Killer’s is. “Your call, boss.”

There’s no question.

Nightmare glances back at Dream. In a single look, the brothers trade a hundred different words. Nightmare spreads his legs just a touch wider, tilting his head; an invitation. Dream kisses him one last time before he moves to take his spot, getting in between Nightmare’s femurs and settling there. He rocks his hips up, letting Nightmare feel the clothed jut of his cock. He shivers, still sensitive from his recent orgasm.

“Sounds like you’re dyin' for more, eh darling?” Killer purrs, rubbing his dick along the side of Nightmare’s face, pressing up near his mouth and smearing wetness along it. “You ready to choke on me?”

Nightmare manages a raised browbone and a laugh, fucked-out as his voice is. “You’ll have to keep me interested. Wouldn’t want to fall asleep.”

Killer’s grin in response is more blade-like than the worst of his knives. Nightmare grins right back, wide and challenging.

At his chest, Cross holds his cock in hand and rubs the head of it against his nipples, then drags it back and forth. He repeats the action twice before using his hands to cup each breast and position his dick in between them. He tests the position out, thrusting his hips a few times before stopping with a pleased sigh, “Fuck boss… can’t wait to cum all over you.”

The earlier exhaustion slips away, excitement overtaking him anew. It’s too early for him to come again, but he has the feeling that he’ll be going a few rounds at least before the night is through. He takes a second to ground himself, to take in each of his partners, and allows himself a small moment of affection for all that they’ve done to pleasure him.

He smiles.

“Then, by all means, have at it.”

**Author's Note:**

> tiddies 😩


End file.
